Antiplatelet therapy and outcomes after aneurysmal subarachnoid hemorrhage: A systematic review and meta-analysis

Background: The efficacy of antiplatelet therapy (APT) after aneurysmal subarachnoid hemorrhage (aSAH) remains unclear. We performed a systematic review and meta-analysis to summarize the associations of APT use after aSAH with outcomes. Methods: We searched published medical literature to identify cohort studies involving adults with aSAH. The exposure was APT use after aSAH. Outcome measures were good functional outcome (modified Rankin Score 0–2 or Glasgow Outcome Scale 4–5), delayed cerebral ischemia (infarcts on neuroimaging), and intracranial hemorrhage. After assessing study heterogeneity and publication bias, we performed a meta-analysis using random-effects models to assess the strength of association between APT and SAH outcomes. Results: A total of 14 studies with 4228 aSAH patients were included. APT after aSAH was associated with good functional outcome (pooled relative risk, 1.08; 95% confidence interval, [CI], 1.02–1.15; I2 = 45%, p for heterogeneity = 0.04), but there was no relationship with delayed cerebral ischemia (pooled relative risk, 0.80; 95% confidence interval, [CI], 0.63–1.02; I2 = 61%, p for heterogeneity <0.01) or intracranial hemorrhage (pooled relative risk, 1.50; 95% confidence interval, [CI], 0.98–2.31; I2 = 0, p for heterogeneity =0.71). In additional analyses, APT resulted in good functional outcomes in endovascularly-treated patients. When stratified by type of medication, aspirin, clopidogrel, and ticlopidine were associated with good functional outcomes. Conclusions: APT after aSAH was associated with a modest improvement in functional outcome, but there was no relationship with delayed cerebral ischemia or intracranial hemorrhage.